package com.yokoboy.hello.rabbitmq;

import com.rabbitmq.client.*;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class RPCServer {

    private static final String RPC_QUEUE_NAME = "rpc_queue";

    private static int fib(int n) {
        if (n == 0) return 0;
        if (n == 1) return 1;
        return fib(n - 1) + fib(n - 2);
    }


    public static void main(String[] argv) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        final Channel channel = connection.createChannel();
        channel.queueDeclare(RPC_QUEUE_NAME, false, false, false, null);
        channel.basicQos(1);
        System.out.println(" [x] Awaiting RPC requests");


        channel.basicConsume(RPC_QUEUE_NAME, false, new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                AMQP.BasicProperties replyProps = new AMQP.BasicProperties.Builder()
                        .correlationId(properties.getCorrelationId()) //
                        .build();


                String message = new String(body, "UTF-8");
                System.out.println(" [.] fib(" + message + ")");
                String response = String.valueOf(fib(Integer.parseInt(message)));


                channel.basicPublish("", properties.getReplyTo(), replyProps, response.getBytes("UTF-8"));
                channel.basicAck(envelope.getDeliveryTag(), false);
            }
        });

    }
}